Answer:
brooo it is rotation .............
Answer: The correct answer is option B.
Explanation:
Mass of the sled = 10 kg
Initial speed of the sled = 2 m/s
Kinetic energy of the sled = 

Work done by the sled = 20 joules
The work done by the friction will be in opposite direction and equal to the magnitude of the work done of the sled that - 20 J.
Hence, correct answer is option B.
Answer: The correct option is (c.).
Explanation:
Mass of the cart A= 1.5 kg
Velocity of Cart A = 1.4 m/s towards right
Mass of the cart B = 1.0 kg
Velocity of Cart B = 1.4 m/s towards left
Momentum (P)= Mass × Velocity

(Negative sign means velocity of the cart is in opposite direction of that of the cart A)
Total Momentum =
Hence, the correct option is (c.).
To develop this problem we will start from the definition of entropy as a function of total heat, temperature. This definition is mathematically described as

Here,
Q = Total Heat
T = Temperature
The total change of entropy from a cold object to a hot object is given by the relationship,

From this relationship we can realize that the change in entropy by the second law of thermodynamics will be positive. Therefore the temperature in the hot body will be higher than that of the cold body, this implies that this term will be smaller than the first, and in other words it would imply that the magnitude of the entropy 'of the hot body' will always be less than the entropy 'cold body'
Change in entropy
is smaller than 
Therefore the correct answer is C. Will always have a smaller magnitude than the change in entropy of the cold object